A layered product that is publicly known according to the related art includes a base material such as one made of a particle board or the like and also a decorative material such as one made of a melamine resin or the like that is laminated on a surface and a side face of the base material. This type of layered product is popularly used as a building material for various types of counters, doors, floors, walls, and the like.
A method for manufacturing this type of layered product that is generally known is as follows. Firstly, a curving process is performed on a surface and a side face of the base material, and then a sanding finish is implemented. Next, the decorative material is adhered to the surface of the base material, and the decorative material is bent while being heated so that the decorative material adheres to the side face of the base material (This process is referred to as the “post form processing”).
At times there is a demand that this type of layered product has, at the curved portion, a small curvature radius being equal to or smaller than 5 millimeters, depending on the intended use of the layered product. When the manufacturing method described above is used, however, because the decorative material made of a melamine resin or the like does not have flexibility, the curvature radius at the curved portion is arranged to be approximately 10 millimeters. Thus, the demand mentioned above is not met.
In order to solve the problem above, according to the related art, a manufacturing method of a layered product has been suggested in which, at first, a cornering side of a base material is cut so that a first cut portion is formed in the base material, whereas a rear surface side of a decorative material is cut so that a second cut portion is formed in the decorative material, and subsequently, the decorative material is bent at the second cut portion. (See, for example, Patent Document 1). According to this method, the thickness of the decorative material is arranged to be smaller so that it is more easily bent. Thus, it is possible to obtain a layered product of which the curvature radius at the curved portion is 2 to 3 millimeters.
According to the method disclosed in Patent Document 1, a cutting tool used for cutting the base material and the decorative material includes a cutting blade (a cutter 8) that has a first cutting plane (a cut portion cutting plane 9), a second cutting plane (a thin portion cutting plane 10) that intersects the first cutting plane, and a sloped plane that connects the first cutting plane to the second cutting plane (See, for example, FIG. 6 in Patent Document 1). Accordingly, according to the method disclosed in Patent Document 1, a corner portion at which the planes intersect each other is formed at the bending portion of the second cut portion in the decorative material. When the stress is concentrated at the corner portion, the decorative material gets damaged. Thus, the ratio of having defective products is extremely high in the current situation. In particular, in order to prevent the decorative material from having linear marks on its surface so as to avoid having a defective product, every time the curvature radius value of the curved portion of the layered product is to be altered, a cumbersome and complicated operation is required so that the positional arrangements of a guiding roller and a guiding pad that are used in the bending process can be finely adjusted. Further, this method requires that a space between the first cut portion in the base material and the second cut portion in the decorative material be filled with an adhesive agent, so that the adhesive agent exhibits a buffering function when the decorative material is bent.
Patent Document 1: JP-A 2004-358873